JDBC数据库连接

第一种方法有点麻烦

package com.hp.util;

import java.sql.*;

public class DBHelper {
    private   static   String  driver="com.mysql.jdbc.Driver";
    private   static   String  url="jdbc:mysql://localhost:3306/usmydb?serverTimezone=Asia/Shanghai";
    private   static   String  username="root";
    private   static   String  password="123456";
    private   static Connection  conn;
    private   static PreparedStatement  ps;
    private   static ResultSet  rs;

    public DBHelper(){}

    static {

        try {
            Class.forName(driver);
            System.out.println("驱动链接成功");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            System.out.println("驱动链接失败");
        }
    }
    public  static  Connection  getConn(){
        try {
            conn= DriverManager.getConnection(url,username,password);
            System.out.println("链接建立成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return   conn;
    }
    public  static  void  close(Connection  conn,PreparedStatement  ps,ResultSet  rs){
        {
            try {
                if(conn!=null)conn.close();
                if (ps!=null)ps.close();
                if(rs!=null)rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) {
        //输出一下   看数据库是否已连接上
        System.out.println(getConn());
    }

}

运行效果:

第二种方法比较简便:

package com.hp.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBHepler {
    public static Connection  getConn() {
        Connection conn= null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String  url="jdbc:mysql://localhost:3306/usmydb?serverTimezone=Asia/Shanghai";
            conn= DriverManager.getConnection(url,"root","123456");
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
        return  conn;
    }
    //输出看一下是否链接
    public static void main(String[] args) {

        System.out.println(getConn());
    }
}

运行效果：